Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (16,460)	$ (16,679)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	699	420
Stock-based compensation expense	8,838	4,978
Amortization of premiums (accretion of discounts) on investments, net	(1,753)
Amortization of debt discount and debt issuance costs	57	39
Amortization of right-of-use asset	281	242
Non-cash interest expense	218
Loss on disposal of property and equipment	144	120
Change in accounts receivable allowances	19	(6)
Provision for excess and obsolete inventories	1	(8)
Changes in assets and liabilities:
Accounts receivable	(1,968)	(2,038)
Inventories	2,109	134
Prepaid expenses and other current assets	(124)	847
Other assets	(17)	(5)
Accounts payable	2,668	19
Accrued liabilities	(6,388)	(3,168)
Other liabilities	(471)	380
Net cash used in operating activities	(12,147)	(14,725)
Cash flows from investing activities
Purchases of property and equipment	(287)	(2,072)
Purchases of investments	(26,407)
Proceeds from maturity of investments	32,800
Net cash provided by (used in) investing activities	6,106	(2,072)
Cash flows from financing activities
Proceeds from issuance of common stock	1,110	168
Net cash provided by financing activities	1,110	168
Net change in cash, cash equivalents and restricted cash	(4,931)	(16,629)
Cash, cash equivalents and restricted cash, beginning of period	55,513	110,463
Cash, cash equivalents and restricted cash, end of period	50,582	93,834
Supplemental disclosure of cash flow information
Cash paid for interest	1,418	582
Noncash investing and financing activities:
Accounts payable and accrued liabilities for purchases of property and equipment	$ 58	$ 638